Grammar Girl here.

Today's topic is something I am very guilty of doing myself: overusing the words so and very.

A listener named Taryn wrote in asking if it is acceptable to write that she is "sooooooo" happy that she is going to the prom (using so with lots of little o's), which got me thinking about not only the word so but also the word very.

Both words are often used as intensifiers, meaning they allow you to express that you are happier than just happy.

In the formal writing world, both words are looked down upon, but so (by itself) is considered worse than very (1).

Misusing So

When you're speaking, emphasizing the word so seems to add punch to a simple statement -- I'm sooooo happy -- and this is why Taryn is tempted to write the word with so many o's: She's used to saying that she's "soooooo" happy, which is fine in informal conversation. But style guides say it should be avoided in writing. There's even a strange discussion in Merriam-Webster’s Dictionary of English Usage about whether using so for emphasis is a distinctly female failing, with the Dictionary concluding that it's a universal error although other commentators link it specifically to women (2).

On the other hand, when so is paired with that, it becomes more acceptable in writing. For example, even though it's considered bad form to write, "I was so happy," it's OK to write, "I was so happy that I jumped for joy." When you say you are so happy that you jumped for joy, so becomes an indefinite adverb of degree instead of a vague intensifier. In other words, so leads into a thought about how happy you were. How happy were you? So happy that you jumped for joy. The grammar mavens find it much more acceptable when so is linked to another clause like that (2, 3).

Overusing Very

Let’s move on. Unlike with the word so, it's not considered a mistake to use the word very by itself for emphasis. Nevertheless, most style guides warn against overdoing it. Instead of saying, "I was very hungry," they encourage you to search for a single more creative adjective -- something like "I was famished," or "I was ravenous." Replacing two simple words like very hungry with one more descriptive word like ravenous makes your writing tighter and usually more interesting, too (4, 5).

Long-time listeners may remember that the issue of very as an intensifier came up when I talked about modifying absolutes. Most people believe that very is out of place and not the best choice in phrases like very unique and very dead, where it modifies something that doesn't have degrees.

Still, very shouldn't be banished from the language. Merriam-Webster's Dictionary of English Usage notes that E.B. White used the repetition of very to excellent effect in a letter, writing, "It was a day of very white clouds, very blue skies, and very dark green spruces." White is the co-author of the famous style guide known as Strunk & White and formally titled The Elements of Style, and I agree that the effect would be lost if White had written, "It was a day of snowy clouds, oceanic skies, and evergreen spruces."

In addition, The Chicago Manual of Style has numerous headings that include the word very: “Very Long Titles,” “Very Wide Tables,” “Very Large Numbers,” and so on. It would seem silly if the guide’s titles were something more creative like “Lengthy Titles,” “Expansive Tables,” and “Humongous” Numbers. Very long, very wide, and very large get the point across more clearly (although Chicago could probably also get away with just long, wide, and large) (6, 7, 8).

Finally, I shouldn't have to tell you this, but just to be safe, very is spelled v-e-r-y. Vary with an a (v-a-r-y) is a verb that means "to differ or change."

Summary

So to summarize, don't use the word so by itself as an intensifier in formal writing, and be careful when you use the word very. It's usually better to use a stronger adjective to describe something than to throw a so or a very in front of a weak adjective. You can use very as an intensifier when it creates a nice effect or is the clearest choice, but make sure you aren't dropping it in just because you're being lazy.